A good portion of it is due to single rail, cap coupled design. It's kind of a transistional unit between the full tube (with transformers) and the direct coupled Solid state units a few years later. It'll sound very much tube like in most respects, IMO. I've got the 2000, 2000A, and 2000X. All sound quite similar to my Fisher Tube receivers and separates. My Pioneer SX-434,737,& 939 are bright and analytical sounding comparatively (the Pioneers are direct coupled). All have been rebuilt so comparisons are valid.
A tired unit can sound muddy when pushed, can clip easier (and you'll hear it ) as Solid state doesn't ramp up the clipping(soft clip) like a tube unit will. It clips HARD and fast. If you don't catch it quick, you can blow the amp. So be careful and try to get it overhauled (rebuilt). There are AK members in spokane and seattle areas that can rebuild it, generally better than a shop, and a bit cheaper too.
Switches are easy to treat with DeOxit. If you can handle a screwdriver, you can deoxit all the switches, again. Sometimes 3-4 applications 3-4 weeks apart will finally get the switches reliable. UNPLUG UNIT and sit on the plug(Safety 1st). Take offthe top and bottom covers. Find an opening in the switch housings. Don't try to spray in from the front, it doesn't work well, (you usually end up changing your shirt). Short spray (spritz) only. Let the Deoxit sit for 30 minutes give each another spritz to wet it again and then work the Bejesus out of them. Also do all the rotary switches and pots (spritz, wait 30, spritz and EXERCISE). Switch hands when tired. Work each switch and pot 40-50 times vigorously. Then finish up with Faderlube or Shield.
